ARCHIVED REPORTS_XR0007397 - Laserfiche WebLink

Home Browse Search

FiFourth Quarter 2000 Ground Water Monitoring Report Cleanup 13nd Abatement Order No. 5-00-707 EAI Project No. 1232 2.4 FIELD INVESTIGATION ..J 2.1 Ground Water Elevation Survey On December 13, 2000, prior to purging or sampling activities, depth measurements to fluid levels were obtained by EAI from all monitoring wells associated with the Wards (MW-1 through MW-7) and Unocal (MW-10 through MW-22D) sites. Depth measurements were obtained using an interface probe accurate to 0.01 foot (see Table 2). No free-product was detected in any of the wells. The water level measurement for each well t was converted to mean sea level (MSL) datum by subtracting the measured water level for each well from its respective "top of well casing elevation" datum (see Table 2). 2.2 Ground Water Sampling On December 13 and 14, 2000, ground water samples were collected by EAT from all ground water monitoring wells associated with the Wards and Unocal sites. Prior to sampling, the wells were purged using a Grundfos MP-1 submersible pump. Temperature, conductivity, pH, and turbidity were recorded to evaluate the effectiveness of purging activities (see Appendix A). The wells were sampled in the order that purging activities were completed. Water samples were collected from each well from just below the water surface using Voss Technologies disposable bottom bailers equipped with volatile 1 : organic compound sampling tips. Use of these bailers precludes the potential for cross- contamination. _ Each water sample was sealed in three 40-milliliter volatile organic analysis (VOA) vials with Teflon septa lined lids. The VOA vials were completely filled so that no head space existed ` between the sample and the lids. The samples were labeled with the sample point identification, preservative added, if any, date, time, and EAI project number, and immediately placed into a chilled ice chest. The samples were kept chilled until delivered to the laboratory for analytical testing. All samples were logged on a chain of custody record form (see Appendix B). 2.3 Sampling Equipment Cleaning Protocol The submersible pump and hose system (Equipment), used only to purge the wells prior to sampling, was decontaminated between each event using the following procedure: • The Equipment was flushed in a solution of Alconox detergent and tap water; and • The Equipment was flushed with tap water. 1_>I BHM:127280092 4 ENVIRONMENTAL AUDIT, INC.©